Clad member and method of manufacturing same

ABSTRACT

A clad member is made up of a plate-like clad base material having on its surface a recessed portion, and solidified portions of a metallic material which is different in kind from the clad base material. The solidified portions are disposed in the recessed portion at a distance from each other and are bonded with the clad base material through melting. The clad member is manufactured by forming an elongated recessed portion on a surface of a plate-like clad base material. The recessed portion is filled with a comminuted metallic material which is different in kind from the clad base material. A laser beam is irradiated onto a plurality of regions which are separated from each other in a longitudinal direction of the recessed portion such that partly melted portions of the comminuted metallic material are generated to thereby bond the comminuted metallic material with the clad base material. The melted portions are solidified. The remaining non-molten portions of the comminuted metallic material are removed.

This is a Division, of application Ser. No. 08/708,584 filed Sep. 5,1996, now U.S. Pat. No. 5,840,418.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a clad member in which a different kindof material is partly embedded in a clad base material. It also relatesto a method of manufacturing the clad member.

In this specification, the term "clad member" means a "metal-cladsemimanufacture" which is made by cladding or overlaying a specifiedmetal on a surface of a "clad base material" which means a base material(i.e., a metal or a ceramic) on which the specified metal is clad oroverlaid.

2. Description of the Related Art

As this kind of clad member, there is conventionally known one which ismanufactured by the following steps Namely, as shown in FIG. 1, a grooveb is formed, by means of rolling or the like, in a clad base material"a" of an elongated copper plate. A strip-like material c, such asnickel, which is different in kind from that of the clad base materialis fitted into the groove b, and the assembly thus obtained is rolledtogether to thereby obtain a clad member in which the different kind ofmaterial is embedded in the longitudinal direction of the clad basematerial. This kind of clad member is then sliced into pieces to useeach of these sliced pieces as a component part for electrical contactof a bimetal, or the like.

The above-described clad member can be manufactured relatively cheaplyHowever, the strip-like material to be embedded into the clad basematerial extends in the longitudinal direction of the clad base material"a." Therefore, if an electrical component part such as shown in FIG. 2is manufactured by means, e.g., of pressing the assembly, there is adisadvantage in that the embedded strip-like material c will be partlywasted as a trash. In case the strip-like material c is made of a raremetal or a noble metal, the loss by this waste becomes enormous. Even ifthe trash is recovered for reuse, the increase in the product cost isinevitable

SUMMARY OF THE INVENTION

The present invention has an object of providing a clad member that isinexpensive and is free from such a waste, as well as a method ofmanufacturing the clad member.

According to one aspect of the present invention, the above object isattained by a clad member comprising: a plate-like clad base materialhaving on its surface a recessed portion; and solidified portions of ametallic material which is different in kind from the clad basematerial, the solidified portions being disposed in the recessed portionat a distance from each other and being bonded with the clad basematerial through melting.

In another example, the clad member comprises: a plate-like clad basematerial having on its surface a plurality of recessed portions; andsolidified portions of a metallic material which is different in kindfrom the clad base material, each of the solidified portions beingdisposed in each of the plurality of recessed portions and being bondedwith the clad base material through melting.

According to another aspect of the present invention, there is provideda method of manufacturing a clad member comprising the steps of: formingan elongated recessed portion on a surface of a plate-like clad basematerial; filling said recessed portion with a comminuted metallicmaterial which is different in kind from the clad base material;irradiating a laser beam onto a plurality of regions which are separatedfrom each other in a longitudinal direction of the recessed portion suchthat partly melted portions of the comminuted metallic material aregenerated to thereby bond the comminuted metallic material with the cladbase material; solidifying the melted portions; and removing remainingnon-molten portions of the comminuted metallic material.

In another example, the method comprises the steps of: forming aplurality of recessed portions on a surface of a plate-like clad basematerial at a distance from each other; filling each of the recessedportions with a comminuted metallic material which is different in kindfrom the clad base material; irradiating a laser beam onto thecomminuted metallic material such that the comminuted material is meltedfor bonding with the clad base material; and thereafter solidifying thecomminuted metallic material.

Preferably, the step of forming a plurality of recessed portions on thesurface of the plate-like clad base material is performed by laserirradiation.

In the above-described "another" example, the step of forming aplurality of recessed portions on the surface of the plate-like cladbase material may comprise the steps of: forming a plurality ofperforated holes in the plate-like clad base material at a distance fromeach other; placing the clad base material on a flat supporting plane;filling each of the perforated holes, up to a predetermined depth, witha comminuted material which is similar to the clad base material;irradiating a laser beam onto the comminuted material such that thecomminuted material is melted for bonding with the clad base material;and thereafter solidifying the comminuted material.

The above-described clad base material is a metallic material or aceramic.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects and the attendant advantages of the presentinvention will become readily apparent by reference to the followingdetailed description when considered in conjunction with theaccompanying drawings wherein:

FIG. 1 is a perspective view of a conventional clad member;

FIG. 2 is a perspective view of one example of a component part which ismanufactured by using the clad member in FIG. 1;

FIG. 3 is a perspective view of an important portion of a first exampleof a clad member according to the present invention;

FIG. 4 is a perspective view of an important portion of a second exampleof a clad member according to the present invention;

FIG. 5 is a schematic diagram to explain a first method of manufacturingthe clad member;

FIG. 6 is a schematic diagram to explain a second method ofmanufacturing the clad member;

FIG. 7 is a perspective view of a clad base material of a third exampleof a clad member to be manufactured by a third method of manufacturingthe clad member; and

FIG. 8 is a perspective view showing an intermediate state ofmanufacturing the clad member in which the plurality of recessedportions have been made using the clad base material shown in FIG. 7.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

In FIGS. 3 and 4, reference numeral 1 denotes a clad base material whichis made up of a metal such as a plate-like copper, cupronickel, nickel,or the like or else of a ceramic. On the surface of this clad basematerial there is formed a dented portion 2 with a forming means in theform of rolling, cutting, or the like. As the clad base material, thereis used an elongated metallic material or a strip-shaped ceramicmaterial. Depending on the use to which a clad member is put, the dentedportion 2 is formed into an elongated groove 2a or into independentdented portions 2b which are scattered in a plurality of portions at adistance therebetween as shown in FIG. 4. Inside the dented portion 2,there is provided a solidified portion (i.e., a portion made byhardening of a molten material) 3 of a metallic material which isdifferent in kind from the material of the clad base material 1. Thesolidified portion is bonded, through melting or fusion, with the cladbase material 1 by melting with a laser beam of a carbon dioxide laseror the like. In case the dented portion 2 is an elongated groove 2a asshown in FIG. 3, the solidified portion 3 is provided in a plurality ofpieces inside the elongated groove 2a at a distance therebetween. Incase the dented portion 2 is made up of independent dented portions 2bas shown in FIG. 4, the solidified portion 3 is provided in each of thedented portions 2b.

It is advantageous to use a rare metal and a noble metal as the metallicmaterial for the purpose of forming the solidified portion 3. If anelectric component part in the shape as shown in FIG. 2 is made bypressing the clad member of the present invention using theabove-described metallic material, the solidified portion 3 can beprevented from becoming a refuse after the pressing work, with theresult that the metallic material in the solidified portion 3 will notbe wasted.

FIG. 5 shows a schematic process diagram of a method of manufacturingthe clad member having an elongated groove 2a as shown in FIG. 3. Insidethe elongated groove 2a there is filled, with a suitable feeding means,a comminuted or finely particulate metallic material 5 such as metallicpowders or metallic foils made up of a material different in kind fromthat of the clad base material 1. A laser beam 7 is irradiated, whilemoving in the X-Y directions, onto regions 6 which are disposed in thelongitudinal direction of the elongated groove 2a while leaving adistance 4 therebetween. By this operation, the comminuted metallicmaterial in each of the above-described regions 6 separated from eachother by the above-described distance 4 is melted. The surface of theclad base material 1 is also subjected to heating at the same time andis also melted depending on the conditions. After the comminutedmetallic material has been solidified or hardened, there are formed aplurality of solidified portions 3 which have been bonded, throughmelting, with the clad base material 1. Since the comminuted metallicmaterial 5 within the range of the above-described distance 4 is in anon-molten state, it can easily be removed from inside the elongatedgroove 2a. As a result of the above-described removal, there can beobtained a clad member in which the solidified portions 3 are presentinside the elongated groove 2a at intervals from each other. Thesolidified portions 3 attain a securely bonded condition as a result ofthe melting combination with the clad base material 1. A higherreliability of combination can be secured than in the case of adhesionthrough pressing.

FIG. 6 shows a schematic process diagram of a method of manufacturing aclad member with a plurality of independent dented portions 2b which aredisposed in the clad base material 1 at a distance from each other. Inthis method, by using a laser beam 7, independent dented portions 2b areformed in the clad base material 1 at a distance 4 from each other.Inside each of the independent dented portions 2b, there is filled, witha suitable feeding means, a comminuted metallic material 5 such as ametallic powder or the like which is made of a material different inkind from that of the clad base material 1 like in the above-describedmethod. The laser beam 7 is irradiated onto each of the independentdented portions 2b to thereby melt the comminuted metallic material 5.At the same time, the surface of the clad base material 1 is also partlyheated and is melted depending on the conditions. Once the comminutedmetallic material 5 is solidified, there is formed a solidified portion3 in which the comminuted metallic material 5 is firmly bonded, throughmelting, with the clad base material 1. Where necessary, the laser beam7 is moved inside the respective independent dented portions 2b tothereby melt the comminuted metallic material 5 in the entire respectiveindependent dented portions 2b. By using the laser beam 7 in forming theindependent dented portions 2b, the independent dented portions 2b canbe easily formed in the ceramic base material 1 which is difficult ofmachining.

The following method may also be employed in forming dented portions 10as shown in FIG. 8 which are conventionally difficult of forming.Namely, as shown in FIG. 7, perforated holes 8 are formed in the cladbase material 1 by means of a laser beam, pressing, or the like. Thisbase material 1 is then placed on a flat supporting plane, and theperforated holes 8 are filled, to a smaller depth (i.e., not up to thelevel flush with the upper surface), with the metallic powder 9 or thelike of a similar composition as the base material. The metallic powderor the like is then melted by means of the laser beam or the like and isthereafter solidified.

An explanation will now be made about specific examples of the cladmember according to the present invention.

EXAMPLE 1

On the surface of a clad base material 1 of elongated copper which has awidth of 40 mm, a thickness of 3 mm, and a length of 1 m, there wasformed, as a dented portion 2, a strip of elongated groove 2a which hasa depth of 1.5 mm and a width of 20 mm over the entire length of theclad base material 1. The clad base material 1 was fed to a carbondioxide laser machining device while filling one end of the elongatedgroove 2a with a comminuted metallic material 5 of gold of a particlesize of 0.05 mm. The laser beam of 2 kw was irradiated onto regions 6while leaving a distance 4 of 10 mm therebetween inside the elongatedgroove 2a. The laser beam 7 with a diameter of 0.2 mm was moved in theX-Y directions to thereby irradiate the entire regions 6 each having awidth of 20 mm and a length of 20 mm. By intermittently moving the cladbase material 1 in the longitudinal direction thereof, the meltedportions 8 of the comminuted metallic material 5 were formed over theentire length of the elongated groove 2a while leaving a distance 4therebetween. The non-melted comminuted metallic material 5 thatremained in the regions corresponding to the distance 4 were recoveredby sequentially sucking after the solidification of the melted portions8. The solidified portions 3 in which the melted portions 6 solidifiedwere bonded, through melting, with the clad base material 1 and had asufficient bonding strength.

EXAMPLE 2

A clad base material 1 of cordierite ceramic having a width of 90 mm, athickness of 3 mm, and a length of 250 m was fed to the above-describedcarbon dioxide laser machining device. By means of the laser beam 7,there were formed in the longitudinal direction on the surface of theclad base material 1 spot-shaped independent dented portions 2b eachhaving a diameter of 5 mm and a depth of 1 mm at a distance of 10 mmtherebetween. After this machining step was completed, the clad basematerial 1 was fed again to the laser machining device while filling theindependent dented portions 2b on the clad base material 1 with acomminuted metallic material 5 of gold with a particle size of 0.05 mm.While moving the laser beam 7 within each of the independent recessedportions 2b, the comminuted metallic material 5 inside each of theindependent recessed portions 2b was melted. The solidified portions 3in which the melted portions 6 solidified were bonded, through melting,with the clad base material 1 with a sufficient bonding strength.

As explained hereinabove, according to the present invention, the cladmember is manufactured by bonding, through melting, the solidifiedportion of the metallic material, which is different in kind from theclad base material, with the clad base material inside continuous orindependent dented portions which are formed on the surface of the cladbase material at a distance from each other. The clad portion of themetallic material which is different in kind from the clad base materialis utilized in manufacturing a desired product. Even if the portionother than the clad portion is discarded as a waste, this discardingdoes not bring about a waste of the metallic material. Therefore, incase a rare metal or a noble metal is used as the metallic material, thecost of the raw materials becomes low. According to the method ofmanufacturing the clad member of the present invention, the clad membercan be manufactured in a relatively inexpensive manner without wastingthe comminuted material.

It is readily apparent that the above-described clad member and themethod of manufacturing the same meet all of the objects mentioned aboveand also has the advantage of wide commercial utility. It should beunderstood that the specific form of the invention hereinabove describedis intended to be representative only, as certain modifications withinthe scope of these teachings will be apparent to those skilled in theart.

Accordingly, reference should be made to the following claims indetermining the full scope of the invention.

What is claimed is:
 1. A method of manufacturing a clad membercomprising the steps of:forming a plurality of perforated holes in aclad base material at a distance from each other; placing said clad basematerial on a flat supporting plane; filling each of said perforatedholes, up to a depth which is a portion of a total depth of each saidrespective perforated hole with a first comminuted material which is ofa material which is the same as said clad base material; irradiating alaser beam onto said first comminuted metallic material such that saidfirst comminuted material is melted for bonding with said clad basematerial; thereafter solidifying said first comminuted metallic materialto form a plurality of recessed portions; filling each of said recessedportions with a second comminuted metallic material which is a differentmaterial from said clad base material; irradiating a laser beam ontosaid second comminuted metallic material such that said secondcomminuted material is melted for bonding with said clad base material;and thereafter solidifying said second comminuted metallic material.